Information AboutSeagrass |
| CATEGORIES ABOUT SEAGRASS | |
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Seagrass (or '''sea-grass''' in British English ) are Flowering Plant s from four plant families ( Posidoniaceae , Zosteraceae , Hydrocharitaceae and Cymodoceaceae ) that grow in the marine saline environment. They are called seagrasses only because most species superficially resemble terrestrial Grass es of the Family Poaceae. Because these plants must Photosynthesize , they are limited to growing submerged in the Photic Zone , and most occur in shallow and sheltered coastal waters anchored in sand or mud bottoms. They undergo Pollination while submerged and complete their entire life cycle underwater. There are about 60 species worldwide (although the Taxonomy is still disputed). Seagrasses form extensive beds or Meadow s, that can be either monospecific (made up of one species) or multispecific (where more than one species co-exist). In temperate areas, usually one or a few species dominate (for instance Eelgrass '' Zostera marina'' in the North Atlantic), whereas tropical beds usually are more diverse, with up to 13 Species recorded in the Philippines . Seagrass beds are highly diverse and productive Ecosystem s, and can harbor hundreds of associated species from all Phyla , for example juvenile and adult Fish , epiphytic and free-living Macroalgae and Microalgae , Shellfish , Bristle Worm s, and Nematode s. Few species were originally considered to feed directly on seagrass Leave s (partly because of their low nutritional content), but scientific Review s and improved working methods have shown that seagrass Herbivory is a highly important link in the food chain, with hundreds of species feeding on seagrasses worldwide, including Dugong s, Manatee s, Fish , Geese , Swan s, Sea Urchin s and Crab s. Seagrasses are sometimes labelled , and the seagrass Root s and Rhizome s stabilize the seabed. Their importance for associated species is mainly due to provision of Shelter (through their three-dimensional structure in the water column), and for their extraordinary high rate of Primary Production . As a result, seagrasses provide Coastal Zone s with a number of Ecological Goods and Ecological Services , for instance Fishing Ground s, Wave Protection , Oxygen Production and protection against coastal Erosion . GENERA OF SEA GRASSES
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